A standard ring-spinning machine has two parallel rows of spindles mounted on a spindle-bank support and rotatable about vertical axes. An endless flat drive belt tangentially engages whorls of the spindles to rotate them about their axes. The advantage of this system is that an individual spindle can be stopped without stopping the other spindles, either simply by braking its whorl so the belt slips on it or by pushing the belt radially away from the spindle whorl of the spindle to be stopped.
In order to avoid excess tension in the belt it is known, for example from German patent document 3,802,200 of H. Wolf, to provide several drives along the belt, in effect subdividing it into several driven sections. To do this a rather thin flat belt is used and two vertically superposed but independently rotatable rollers are used between two adjacent spindles. The belt is deflected around one of the rollers to a drive wheel and then extends back to the other roller, undergoing a vertical offset established by setting the drive wheel to rotate about an axis forming a small acute angle to the vertical and by setting the two deflector rollers at similar but oppositely tipped angles. This system is fairly effective, but requires that a fairly thin belt be used and that the whorls be fairly long. Since some of the whorls will be engaged by the belt high and some low, force transmission is not as exact as it would be with a standard center engagement with a wide belt.
Another arrangement described in German patent document 3,916,363 of T. Kato et al eliminates the deflector rollers and simply puts the drive wheel at the same level but offset from the row of spindle whorls. The resultant drive force is fairly uneven, however, as the belt will be quite tight on the incoming side and loose on the outgoing side. Furthermore it becomes difficult or impossible to stop or brake the spindles immediately flanking the drive location.